<!DOCTYPE html>
<html>
<script>
function loadNextForm(){
window.location = 'form2.html';
}
</script>
<body>

<h2>HTML Form 1</h2>

<form onSubmit='\' method='post'>
  First name:<br>
  <input type='text' id='firstname' >
  <br>
  Last name:<br>
  <input type='text' id='lastname'>
  <br><br>
  <input id='submitForm1' type='button' value='Submit' onclick='loadNextForm()'>
</form>
</body>
</html>